In the fabrication of semiconductor chips, multiple chips are commonly fabricated simultaneously together on a large wafer. When the wafer is completed, it is then necessary to separate, or “singulate”, the individual chips from one another. One typical process for singulating the chips is to cut the wafers with precision diamond saws that isolate the individual chips from one another by the width of the saw. To protect the chips and the wafer during this singulation process, an adhesive tape is commonly first applied to a surface of the wafer, generally to the bottom surface.
Following singulation, it is then necessary to remove the chips individually from the adhesive tape. Unfortunately, as technological advances have continuously reduced the dimensions and thicknesses of chips, they have become increasingly fragile and subject to cracking during removal from the adhesive tape. Thus, product losses have been continually increasing, whereas competitive pressures for lower prices and increased production efficiency have made such product losses ever increasingly intolerable.
Various solutions have been attempted to mitigate this problem. For example, careful adjustments have been made to the adhesive strength of the tape to reduce the tape holding force on the chip to just the minimum that is feasible. However, the tape holding force must be sufficient to secure the chips during the singulation sawing process. With the ever accelerating reduction in chip sizes and thicknesses, it is ever more and more difficult to lift or pull the individual chips off of the adhesive tape without cracking the chips, regardless of the adhesive strength. This is particularly true, for example, for conventional peeling methods such as those that use needles to push the chips off of the adhesive tape.
Unfortunately, therefore, as the chips become ever thinner (for example, below 125 μm thickness), the chips become ever more vulnerable to random chip cracking during chip peeling from the tape. This renders the chips unavailable for subsequent bonding to upcoming production objects such as printed circuit boards, substrates, leadframes, and so forth. This makes production delays and losses even worse.
Thus, a need still remains for significant improvements in systems for peeling singulated semiconductor chips from tape during the fabrication thereof. In view of increasing competitive pressures, increasing production volumes and production demands, declining profit margins, and the ever decreasing physical sizes and strengths of semiconductor chips, it is increasingly critical that answers be found to these problems.
Solutions to these problems have been long sought but prior developments have not taught or suggested any solutions and, thus, solutions to these problems have long eluded those skilled in the art.